JP2005088746A - Hybrid car - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hybrid car assuring simple driving operations, capable of lessening the operating ends for the driving operations, and of selecting reasonably internal-combustion engine running and electric running according to the running mode despite by simple driving operations. <P>SOLUTION: A one-way clutch is used to the output shaft of an internal-combustion engine so that no clutch control takes place. A program-controlled clutch is installed between two motor generators. A transmission gear is of planetary type. The motor generators should be two pieces of approximately the same specifications. The starting mode is made with the motor generator, in which a torque converter having a large heat loss due to slip is not used. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a hybrid vehicle that can perform start, acceleration, steady running, and regenerative braking by rationally automatically controlling the flow of energy by a simple driving operation. The present invention relates to a new type of hybrid vehicle including an internal combustion engine and two motor generators and provided with a one-way clutch on an output shaft of the internal combustion engine.

Hybrid vehicles can be broadly divided into series and parallel types. In series hybrid vehicles, a generator is connected to the output rotation shaft of the internal combustion engine, and electric energy generated by this generator is charged to the battery and taken out from this battery. In this form, electric energy is supplied to an electric motor connected to a drive shaft to drive the vehicle. The electric motor connected to the drive shaft is controlled so as to act as a generator during braking, and the electric energy generated by the braking charges the vehicle battery. This is regenerative braking.

  On the other hand, in the parallel hybrid vehicle, the output rotational power of the internal combustion engine is supplied to the axle, and the motor generator is mechanically connected to the axle or the rotational shaft of the internal combustion engine. The electric system of the motor generator is connected to a vehicle battery via an inverter. In this form, the electric generator stored in the battery is supplied by operating the motor generator as an electric motor at the time of starting acceleration or climbing when the driving force of the internal combustion engine is insufficient. During downhill or deceleration, the motor generator is operated as a generator to act as electric braking on the vehicle, and the generated electric energy is regenerated in the battery. As described above, various configurations are known for the type in which the motor generator is connected to the axle and the type in which the motor generator is connected to the internal combustion engine, each of which has its own characteristics.

  Regarding the hybrid vehicle in which two motor generators are connected in series to the rotating shaft through clutches on the output shaft of the internal combustion engine, the following [Patent Document 1] (Applicant, Equos Research) and the following [Patent Document] 2] (Applicant, Equos Research).

  On the other hand, the applicant of the present application has applied for a patent for a configuration using a one-way clutch for the rotating shaft of an internal combustion engine of a hybrid vehicle (see [Patent Document 3] below). The one-way clutch is a unidirectional rotational power transmission means having a structure equivalent to a ratchet used for a bicycle rear wheel. By using the one-way clutch, when the internal combustion engine accelerates the axle, the internal combustion engine is connected to the output shaft, and when the internal combustion engine is accelerated from the axle, the clutch automatically idles and the axle Is not transmitted from the engine to the internal combustion engine.

  Further, the applicant of the present application has filed a patent application for improvement of a hybrid vehicle using a one-way clutch (see Japanese Patent Application No. 2002-180158 (not disclosed at the time of filing this application)). This is an improvement so that the engine brake can be used even if the one-way clutch is used.

Regarding the structure of a hybrid vehicle using a one-way clutch, the inventors of the present application gave a lecture at a symposium of the Japan Society for Automotive Engineers on May 23, 2002. It is described and distributed. In this [Non-Patent Document 1], there is a specific description of the structure of the one-way clutch, the structure for absorbing the shock when engaged, the external shape of the prototype device, and the like.
JP-A-6-144020 Japanese Patent Laid-Open No. 7-135701 JP 2001-206084 A Masuda et al. “Indirect Series Parallel Hybrid Bus” published by the Japan Society of Automotive Engineers, JSAE SYMPOSIUM No.06-02 “Hybrid Technology Entering Practical Use” Lecture No. 20024221

Hybrid vehicles are now in practical use, and their performance is improving, and fuel consumption per mileage is in the direction of economics. When designing an economical hybrid vehicle, we were faced with the problem that it was necessary to operate it properly. Often, hybrid vehicles sold are not operated with fuel consumption as designed, which is one of the main reasons for not operating properly. In other words, when a hybrid vehicle is being used for a specific consumer, the driver who drives the hybrid vehicle is given appropriate training and guidance, and measures are taken to rationally operate the hybrid vehicle. Can be implemented. However, when hybrid vehicles are widely sold and used as private cars, it is difficult to give specific training and guidance to all drivers. In other words, it is necessary to design such that the characteristics of a hybrid vehicle can be utilized even by a simple driving operation equivalent to a widely used general vehicle.

  As a hybrid vehicle, fuel and other economics, as well as major problems related to driving operations necessary to reduce harmful black smoke and exhaust gas, are: (1) When to use the internal combustion engine at start-up and acceleration and Appropriately select the time and appropriately select the ratio of the output shared by the internal combustion engine, (2) Reduce clutch friction or torque converter heat loss during running, especially when starting, (3) When the transmission is operated at an appropriate timing, (4) the rotation of the internal combustion engine is stopped as much as possible during steady running, and (5) the internal combustion engine is most efficient when rotated during steady running. (6) Regenerative braking is performed as much as possible at the time of deceleration, and the battery is charged effectively.

  In addition, the hybrid vehicle needs to be replenished if the mounted battery is not properly charged. This must be performed by converting a current obtained from a commercial power source into a direct current using a special charging device while the vehicle is stopped. Whether or not it is necessary to perform supplementary charging during operation and whether or not it is necessary to perform supplementary charging frequently depend on the driving operation.

  In order to simplify the driving operation, the series system described above is considered advantageous. That is, the idea is that all energy required for traveling is once converted into electric energy and stored in the on-vehicle battery. However, in order to convert the rotational energy generated by the internal combustion engine into electrical energy, it is inevitable that there is a corresponding loss. Therefore, there is a limit to improving energy efficiency in the form of converting everything into electrical energy. In other words, it is theoretically advantageous to use the rotational energy generated in the internal combustion engine as it is as rotational energy necessary for vehicle travel as much as possible.

  Next, in the technology (equos) disclosed in [Patent Document 1] and [Patent Document 2] described as the above prior art, the characteristics of the two motor generators are different, and the operation sharing area is different. Explained. For example, see paragraphs [0031] to [0034] and others of [Patent Document 1]. This means that if two motor generators are operated at the same time, neither of them can be used in the most advantageous operating area as two motors or generators, and each of the two motor generators will be enlarged. Understood.

  The present invention has been made against such a background, and an object thereof is to provide a hybrid vehicle with a simple driving operation. That is, an object of the present invention is to provide a hybrid vehicle that can always travel economically and can travel with less exhaust gas without depending on the driver's personal driving skill. An object of the present invention is to simplify the driving operation of a hybrid vehicle by reducing the number of operation ends operated at the driver's seat. In the present invention, there is a great difference in fuel economy due to a difference in driving operation, a generation of harmful exhaust gas is increased due to a difference in driving operation, or it is often necessary to perform replenishment charging due to a difference in driving operation. An object is to provide a hybrid vehicle that does not. Another object of the present invention is to provide a hybrid vehicle having a structure in which the motor generator can be reduced in size.

  The first feature of the hybrid vehicle of the present invention is that the clutch (2) provided on the output shaft of the internal combustion engine (1) is a one-way clutch, and no clutch operation and control are required. This frees the driver from clutch operation. As described above, the one-way clutch is automatically connected when rotational power is output from the internal combustion engine, and is not operated or controlled in any way when the internal combustion engine is forced to rotate by the rotation of wheels. The clutch will automatically idle. The numbers in the parentheses are reference numbers for the embodiment drawings to be described later. This is provided to facilitate understanding of the present invention, and is not intended to limit the present invention to the configuration of this embodiment. The same applies to the following description.

  Furthermore, the configuration of the present invention is characterized in that an automatic transmission including a planetary gear is used as the transmission gear (6). As a result, the driver is freed from any shifting operation during traveling.

  Furthermore, the apparatus of the present invention has a structure in which the rotating shafts of the two motor generators (3, 5) are connected in series by the second clutch (4), and is supplied to each field winding of the two motor generators. The program control circuit (10) controls the rotational phases of the two multi-phase alternating currents, the start or stop of the internal combustion engine, and the opening and closing of the second clutch (4). This configuration eliminates the need for the driver to operate the second clutch (4).

  Furthermore, in the start mode for starting the vehicle from the stopped state, the device according to the present invention operates with one or two motor generators (3 or 5) as motors in principle with the internal combustion engine (1) stopped. To start the vehicle. This eliminates the need for so-called clutch operation for adapting the rotational power generated by the internal combustion engine to the vehicle speed. As a result, both the first clutch (2) and the second clutch (4) can be prevented from slipping. At the same time, frictional heat loss caused by slipping of the clutch does not occur at all.

  Then, in the acceleration mode for accelerating the started vehicle, the internal combustion engine is started for the first time, and powerful acceleration is realized using the output of the internal combustion engine. No operation is required for starting the internal combustion engine and connecting the output shaft. This is executed under the control of the program control circuit. Under the control of the program control circuit, it is possible to set so as to use an effective region of the generated torque with respect to the rotational speed of the internal combustion engine. As a result, the load sharing between the internal combustion engine and the electric motor during acceleration can be set rationally, and therefore control can be performed so as to suppress the generation of harmful exhaust gas such as black smoke generated by the internal combustion engine. Also at this time, there is no state in which the clutch slides, and no energy loss due to torque conversion occurs. The acceleration mode is not limited to the case immediately after starting, but is set as needed when accelerating from a low speed while driving, or in the case of climbing, etc. It is the same.

  In the steady running state, the program control circuit monitors the state of charge of the battery (9), and automatically stops the rotation of the internal combustion engine if the charge capacity is sufficient. At this time, no fuel consumption occurs and the one-way clutch (2) is autonomously idled. When steady running by electric running continues and the amount of charge of the battery (9) decreases, the program control device detects this and automatically starts the internal combustion engine (1). At this time, it is possible to charge the internal combustion engine (1) with a part of the power required for traveling, or to drive the generator by the output of the internal combustion engine and perform charging. That is, at this time, the two motor generators (3, 5) can both be used as motors, or the first motor generator (3) is used as a generator and the second motor generator (5) is used. The mode of charging electric travel can be set by operating as an electric motor. This can automatically take in the driving state, the amount of charge of the battery (9), and the required driving power and automatically create an optimum state.

  When decelerating the vehicle speed, the rotation of the internal combustion engine is stopped in response to the operation of the accelerator pedal and the brake pedal, and one of the motor generators or the The two are controlled so as to be generators, and automatic control is performed so as to execute regenerative braking that is as effective as possible.

  That is, the present invention relates to an internal combustion engine (1), a first clutch (2) connected to the output shaft of the internal combustion engine (1), and an output shaft of the first clutch (2). The connected first motor generator (3), the second clutch (4) connected to the rotating shaft of the first motor generator (3), and the output shaft of the clutch (4) The transmission gear includes a second motor generator (5) to which a rotating shaft is connected, and a transmission gear (6) having an input shaft connected to an output shaft of the second motor generator (5). In the hybrid vehicle in which the output shaft is connected to the propeller shaft (7), the first clutch (2) is automatically coupled in the rotational direction for supplying rotational power from the internal combustion engine (1). It is characterized by being. The transmission gear (6) is an automatic transmission, and preferably includes a planetary gear.

A program for controlling rotation phases of two multi-phase alternating currents applied to respective field windings of the two motor generators (3, 5), starting or stopping of the internal combustion engine, and opening / closing of the second clutch (4) Comprising a control circuit (10), this program control circuit comprising:
(I) a start mode in which rotation of the internal combustion engine (1) is stopped and one of the two motor generators (3, 5) is used as an electric motor;
(Ii) an acceleration mode in which the internal combustion engine (1) is rotated, the second clutch (4) is closed, and at least one of the motor generators (3, 5) is driven as an electric motor;
(Iii) a steady running mode in which the internal combustion engine (1) is rotated or stopped and at least one of the two motor generators (3, 5) is driven as an electric motor; and (iv) the rotation of the internal combustion engine is stopped. Means for switching and selecting one of operation modes including a regenerative braking mode in which at least one of the two motor generators (3, 5) is operated as a generator, and the internal combustion engine in each mode according to battery state information And means for automatically controlling the rotation or stop of (1).

  It is desirable that the two motor generators (3, 4) have the same rated capacity. Thereby, the form which utilizes an electric motor or a generator effectively in the wide range of the shared torque characteristic with respect to a rotational speed is obtained. Thereby, the whole apparatus can be reduced in size.

As described above, the device of the present invention can start, stop, and adjust the speed only by operating the accelerator pedal and the brake pedal, and the optimum hybrid vehicle configuration is automatically selected according to each mode. Will be set. In the apparatus according to the present invention, the speed change lever operated by the driver is only distinguished between forward, reverse, neutral and parking, and no speed change operation which is executed by the driver judging the traveling state is required. Since the start / stop of the internal combustion engine is automatically executed according to the operation mode, there is no need for any driving operation related to the start / stop of the internal combustion engine. In other words, this configuration makes the driving operation very simple, resulting in a large difference in fuel consumption due to a difference in driving operation, an increase in the amount of harmful exhaust emissions due to a difference in driving operation, or a difference in driving operation. The need for battery replenishment charging will not occur frequently.

The structure and operation of the present invention will be described in more detail with reference to the drawings of the embodiment apparatus. FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention. The output shaft of the internal combustion engine 1 is connected to the rotating shaft of the first motor generator 3 via the one-way clutch 2, and the rotating shaft of the first motor generator 3 is connected to the second electric motor via the clutch 4. The rotating shaft of the second motor generator 5 is connected to the propeller shaft 7 via the transmission gear 6. Here, the transmission gear 6 is an automatic transmission configured by a planetary gear.

  The one-way clutch 2 is automatically connected when the internal combustion engine 1 drives the rotation shaft of the first motor generator 3, and the first motor generator 3 drives the rotation shaft of the internal combustion engine 1. In the state, it automatically becomes a detachment state or a sliding state. As described above, the structure of the one-way clutch 2 is a structure known in [Non-Patent Document 1] and others, but this will be briefly described. This is a machine equivalent to a ratchet mechanism provided on the rear wheel of the bicycle. It is a structure. It is automatically coupled or separated according to the direction of power transmission, and no control for coupling or separation is performed from the outside. That is, in a state where driving force is supplied to the output shaft of the internal combustion engine 1, the one-way clutch 2 is in a coupled state. When a force is applied to drive the internal combustion engine 1 from the motor generator 3 side, the one-way clutch 2 automatically enters a disengaged state and idles.

  The clutch 4 is an electromagnetic control type clutch. The clutch 4 is controlled to open and close via an input / output interface (I / O) by a control output of the program control circuit 10.

  The first motor generator 3 and the second motor generator 5 are of the same standard in this embodiment device, and their rotation shafts are connected in a straight line via the clutch 4. It is one of the features of the present invention that the two motor generators 3 and 5 are of the same standard.

  The two motor generators 3 and 5 are each a multiphase AC rotating machine, and the AC current for the field windings is individually supplied by the inverter 8. The two motor generators 3 and 5 are supplied with AC currents that are individually phase controlled. The DC terminal of the inverter 8 is connected to the battery 9. The operation of the inverter 8 is controlled by the program control circuit 10. The terminal voltage and current of the battery 9 are detected by the sensor 13 and input to the program control circuit 10 via the input / output circuit (I / O).

  The program control circuit 10 will be described. Operation information of the accelerator pedal 11 and the brake pedal 12 is input to the program control circuit 10 via an input / output circuit (I / O). In addition to the detection signal of the battery sensor 13, the program control circuit 10 includes the rotation information a of the internal combustion engine 1, the rotation information b of the first motor generator 3, and the rotation information c of the second motor generator 5. , And rotation information (vehicle speed information) d of the drive shaft 7 are input via an input / output circuit (I / O). The control output of the program control circuit 10 controls the rotational phase speed of the inverter 8 as well as starting control information (S) of the internal combustion engine 1, fuel control information (F) of the internal combustion engine 1, and opening / closing control information of the clutch 4. It is. Each is sent to drive hardware via an input circuit (I / O).

  The operation of the apparatus configured as described above will be described according to each operation mode. FIG. 2 is a diagram schematically showing the operation mode, in which time is plotted on the horizontal axis and the vehicle speed is plotted on the vertical axis. The start mode (i) is an operation mode from a stop state to a state where the vehicle starts to move. In this start mode (i), the device of the present invention stops the rotation of the internal combustion engine 1 and operates the motor generators 3 and 5 as motors to start the vehicle. At this time, the clutch 4 is maintained in the coupled state. That is, the internal combustion engine 1 is not used for starting. As a result, operations such as temporarily maintaining the clutch in a slipping state by the driver's clutch operation or generating a low-speed starting torque using the torque converter are not performed. Therefore, the driving operation is simplified and no energy loss is consumed by the clutch or the torque converter.

  The acceleration mode (ii) in FIG. 2 is an operation mode for accelerating to a steady speed after the vehicle starts. When the vehicle speed exceeds a predetermined value, the internal combustion engine 1 is started by automatic control of the program control circuit 10. This predetermined value is a value in the vicinity of the lower limit value of the rotational speed at which effective rotational torque can be extracted from the internal combustion engine 1, and is set to, for example, 5 to 15 km / h in terms of the vehicle speed. When the internal combustion engine 1 is started and the rotational speed increases, the one-way clutch 2 is automatically engaged and the rotational output of the internal combustion engine 1 is sent to the propeller shaft 7. The vehicle is accelerated in accordance with the driver's operation of the accelerator pedal 11.

  In this acceleration mode (ii), it is possible to control to use only the most effective region of the output torque characteristic of the internal combustion engine 1. That is, FIG. 3 shows a characteristic indicating the output torque with respect to the rotational speed of the internal combustion engine, and a region indicated by hatching is a region where the output efficiency with respect to the fuel consumption of the internal combustion engine is maximized. At the time of switching to the acceleration mode (ii), there is already a corresponding vehicle speed, and at the stage of accelerating to the cruise speed, the transmission gear 6 is automatically changed to the optimal combination. The vehicle can be accelerated while using. In a state where the internal combustion engine operates in this region, the combustion inside the internal combustion engine is in the best state, and the state of the exhaust gas is also maintained in the best state with few incombustible components.

  When the vehicle is accelerated and reaches the cruising speed, acceleration is not performed according to the operation of the accelerator pedal 11 by the driver, and the steady running mode (iii) shown in FIG. 2 is entered. For example, the traveling speed is 40 km / h in an urban area, 60 km / h on a normal road, and 100 km / h on a highway. In this state, the travel energy required per unit time is small. The program control circuit 10 monitors the state of charge of the battery 9, and if the state of charge is sufficient, the fuel supplied to the internal combustion engine 1 is shut off (or the ignition system is shut off) to stop the rotation of the internal combustion engine 1. If the charged state of the battery 9 is insufficient, the internal combustion engine 1 can be controlled to continue to drive the vehicle. When the state of charge of the battery 9 is very small, one or both of the motor generators 3 and 5 are controlled by the generator while the internal combustion engine 1 is driven to rotate so that the vehicle is driven and the battery 9 is charged. can do. As described above, even when the internal combustion engine 1 is rotated in the steady travel mode, the corresponding rotational speed can be maintained, so that a region with good fuel efficiency can be used.

  The operating characteristics shown in FIG. 4 qualitatively explain the sharing between the internal combustion engine and the electric motor in the acceleration mode (ii) or the steady running mode (iii). In the apparatus of the present invention, as described above, in the mode of accelerating the vehicle, the internal combustion engine is designed to supplementarily generate driving force using only the region with the best speed torque characteristic. And in the area | region where the rotational speed of an engine becomes large and the area | region where it becomes small, it controls so that driving | operation of an internal combustion engine is stopped as much as possible, and driving | running | working with an electric motor is performed.

  Returning to FIG. 2, the deceleration mode (iv) is started by a driving operation in which the accelerator pedal 11 is released. In some cases, the brake pedal 12 is depressed following the release of the accelerator pedal 11. When the deceleration mode (iv) is entered, even when the internal combustion engine 1 is rotating, the rotation is automatically stopped. As a result, the one-way clutch 2 automatically enters the idle state. And the phase rotation speed of the field winding which supplies the motor generators 3 and 5 so that it may become a generator is controlled. At this time, the program control circuit 10 converts the phase rotation supplied to the field windings of the motor generators 3 and 5 in accordance with the depression amount of the brake pedal 12 so as to convert as much traveling energy as possible into electric energy. Adjust the speed.

According to the present invention, a hybrid vehicle having high efficiency and low exhaust gas can be realized by a simple driving operation without requiring skill in the driving operation. Therefore, it can be used as a general private vehicle or a commercial vehicle.

The block block diagram of this invention Example apparatus. The figure explaining the running mode of vehicles. The figure explaining the area | region where an internal combustion engine is utilized with this invention Example apparatus. The figure explaining the assignment area | region of the electric motor of this invention Example apparatus and an internal combustion engine.

Explanation of symbols

1 Internal combustion engine 2 One-way clutch 3 First motor generator 4 Clutch 5 Second motor generator 6 Transmission gear 7 Propeller shaft 8 Inverter 9 Battery 10 Program control circuit 11 Accelerator pedal 12 Brake pedal 13 Sensor

Claims (5)

An internal combustion engine (1), a first clutch (2) coupled to the output shaft of the internal combustion engine (1), and a first clutch whose rotational shaft is coupled to the output shaft of the first clutch (2). The motor generator (3), the second clutch (4) connected to the rotating shaft of the first motor generator (3), and the rotating shaft connected to the output shaft of the clutch (4). A second motor generator (5), and a transmission gear (6) having an input shaft connected to the output shaft of the second motor generator (5). The output shaft of the transmission gear is a propeller. In the hybrid vehicle connected to the shaft (7),
The hybrid vehicle according to claim 1, wherein the first clutch (2) is a one-way clutch that is automatically engaged in a rotational direction in which rotational power is supplied from the internal combustion engine (1).   The hybrid vehicle according to claim 1, wherein the transmission gear (6) is an automatic transmission. The hybrid vehicle according to claim 2, wherein the automatic transmission includes a planetary gear. A program for controlling rotation phases of two multi-phase alternating currents applied to respective field windings of the two motor generators (3, 5), starting or stopping of the internal combustion engine, and opening / closing of the second clutch (4) A control circuit (10),
This program control circuit
(I) a start mode in which rotation of the internal combustion engine (1) is stopped and one or both of the two motor generators (3, 5) are used as an electric motor;
(Ii) an acceleration mode in which the internal combustion engine (1) is rotated, the second clutch (4) is closed, and at least one of the motor generators (3, 5) is driven as an electric motor;
(Iii) a steady running mode in which the internal combustion engine (1) is rotated or stopped and at least one of the two motor generators (3, 5) is driven as an electric motor; and (iv) the rotation of the internal combustion engine is stopped. Means for switching and selecting one of operation modes including a regenerative braking mode for operating at least one of the two motor generators (3, 5) as a generator;
The hybrid vehicle according to claim 2, further comprising means for automatically controlling rotation or stop of the internal combustion engine (1) in each mode in accordance with battery state information. The hybrid vehicle according to claim 3, wherein the rated capacity of the two motor generators (3, 5) is set substantially equal.

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